The damaging effects of sunlight on human skin have long been noted. In general terms, harmful ultra-violet (UV) rays, particularly those originating from sunlight, which penetrate the upper atmosphere and reach the earth's surface can be classified into two types: (i) high energy UV-B rays (290-320 nm wavelength), which are absorbed just above the dermis and are responsible for sunburn and tanning effects; and (ii) low energy UV-A rays (320-400 nm wavelength), which penetrate deeper into the skin (to the dermis and beyond), and which cause damaging effects that are more long term in nature, such as skin ageing.
One method for delivering sunscreen compositions to the skin and hair is in the form of a finely dispersed spray. This form of product delivery offers improved product coverage on the skin or hair and allows easier application on difficult to reach areas. Such a spray is desirably delivered using a spray pump or canister, which may or may not require the use of pressurized containers or special aerosolizing gases. The ability of such spray-driven delivery systems to deliver a product as a finely dispersed spray is dependent upon the viscosity of the composition at the exit port of the pump. As the viscosity of the composition decreases, the spray becomes more dispersed and yields a more desirable delivery. Conversely, as the viscosity increases, the spray becomes less dispersed and more stream-like, yielding a less desirable delivery.
A further consideration is the form that the composition is provided on the skin. It is well known that gel-type compositions exhibit desirable tactile and “feel” properties to the skin. However, gels suitablely have a relatively high viscosity, as compared to liquids, and may thus be unsuitable for use in spray sunscreen applications. Accordingly, a spray sunscreen that is dispensed in the form of a finely dispersed spray, while simultaneously having desirable feel properties as applied to the skin, remains elusive.
Thus, there remains a need in the art for sprayable sunscreen composition having desirable viscosity and feel properties. In particular, it would be desirable to provide a sunscreen in gel form, but that is also dispensable as a spray. Still further, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with this background of the inventive subject matter.